set 1 MCQ Questions & Answers Detailed Explanation

Question : 1

Which one of the following statement is not true ?

a) The total number of neutrons and protons is always equal in a neutral atom

b) The total number of electrons and protons in an atom is always equal

c) Most of the space in an atom is empty

d) The total number of electrons in any energy level can be calculated by the formula 2n²

Question : 2

In which one of the following is the valence electronic configuration, ns²np³ found ?

a) Nitrogen

b) Oxygen

c) Carbon

d) Argon

Question : 3

The total number of atoms represented by the compound CuSO₄ .5H₂O is

a) 21

b) 5

c) 27

d) 8

Question : 4

In atom, neutron was discovered by

a) Chadwick

b) Rutherford

c) J.J. Thomson

d) Newton

Question : 5

The isotopes of an element have

a) same atomic number

b) same mass number

c) same number of neutrons

d) None of these

Question : 6

An atom of carbon has 6 protons. Its mass number is 12. How many neutrons are present in an atom of carbon?

a) 10

b) 6

c) 12

d) 14